Construction of a PEO/Mg–Mn LDH composite coating on Mg–Ag–Mn alloy for enhanced corrosion resistance and antibacterial potential

Endowing magnesium alloys with both durable antibacterial ability and reliable corrosion resistance is an urgent task for the development of magnesium-based implants. In this work, Mg–Mn layered double hydroxide (LDH) intercalated with organic salicylic acid (SA) anion was synthesized on a PEO-coated Mg–Ag–Mn alloy via the combination of co-precipitation and hydrothermal treatments. The PEO layer endows Mg–Ag–Mn alloy with a moderate corrosion barrier and the Mg–Mn LDH layer not only seals the PEO defects, but also acts as a reservoir for antibacterial agents (namely SA). The PEO/Mg–Mn LDH composite coating on Mg–Ag–Mn alloy dramatically increases its corrosion resistance by up to 3 orders of magnitudes, which also tailors the ionic release kinetics for a desired antibacterial potential to prevent bacterial infection.